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Comment by boomboomsubban | Hacker News Reader

Though I cognitively understand why it's the case, the fact that operating on the brain isn't painful still weirds me out. Something about the part of the body that processes pain not feeling pain feels bizarre even though I can see why there'd be no benefit to having pain receptors there.

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The way it usually works is that we have anesthesia put the patient entirely to sleep to start and then we wake them for the sensitive part of the case when we need to perform stimulation and cognitive testing. We use local anesthetic like lidocaine and marcaine on the scalp while opening to minimize pain when temporarily awake. Then the patient goes back to sleep for closing. It’s a tough balance for the anesthesiologists to maintain —- they are as critical to the procedure as the neurosurgeon is.

The couple of times I've woken up from anaesthesia, I was apparently pretty rambly and nonsensical for awhile. I wonder if I'd be able to play piano like that. To some extent, playing is automatic, sub-verbal for me. Maybe it would come out great and I just wouldn't remember it, but... how do you gauge the performance given that they're still coming out of anaesthesia?

While I'm asking, there's a question that's been driving me crazy since a recent colonoscopy where I was sedated with fentanyl and (? something like diazepam). I think I remember being awake and remembering most of the procedure immediately afterwards, but within about an hour I couldn't remember anything except one moment when I was in pain and shouting that I was going to explode, as a nurse put another ampule in the drip line. What's bugging me is, was I really experiencing pain like that and aware the whole time, and the drugs just erased my memory of it afterwards? Or was that just a breakthrough moment in an otherwise uneventful procedure where I felt relatively little?

In the US, I think propofol has largely replaced diazepam for colonoscopies. Whether that's what you had, this sounds like your experience:

>Subclinical doses of propofol produce anterograde amnesia, characterized by an early failure of memory consolidation.[0]

I'm going to talk to the doctor for my next one about skipping the drugs. I've heard it's unpleasnat but not too painful.

[0] https://www.sciencedirect.com/science/article/pii/S000709121...

[1] https://academic.oup.com/bja/article/96/3/289/325896

Propofol would be for heavy sedation and would require an anesthesiologist or nurse anesthetist to be present. My insurance didn't cover that. I checked, and what I got was Versed (midazolam) + fentanyl.

At least in my prior experience with benzodiazepines like Xanax or lorazepam, they didn't cause any amnesia. I've never had fentanyl or any synthetic opioid besides during this procedure, so maybe that was what caused the amnesia. Or maybe there was no amnesia, and I was just so stoned from the combination that I was asleep and didn't really experience much except when some pain woke me up... I guess that's what I'm wondering.

Wouldn't it be excruciatingly painful to get to the brain though? Or is there a way to locally anaesthetize so that you don't feel your scalp being sliced open and your skull being cracked open?

I think that it’s less about the pain because yeah you could probably use some sort of a local anesthetic for the scalp tissue, but I can’t imagine what all the vibrations and sounds passing through skull feels like, especially when power tools are used to drill into the skull or cut out a small section.

If the drill is medical grade and extremely fast, you might not feel any vibrations at all, almost like a laser. Should feel like a scrape more than anything.

I don't know what you (personally) imagine when you say 'medical grade', but surgery (other than robots and keyhole I suppose) is pretty brutal and mechanical. A 'medical-grade drill' is basically whatever's been approved for medical use, not (necessarily, though I don't doubt they exist) something special that isn't also sold for drilling masonry.

When I’ve had surgery that was the joke the doctor told. It’s just a $10,000 version of a tool you’d pick up at Home Depot.

Obviously there are some things that would be different. For example a big issue is you’d want to use non-toxic lubricant on all the parts. Not sure what non-toxic means but I’m sure there is something (vegetable oil? Silicone?)

You’d also want to make sure it won’t fling off tiny metal or plastic shards from the tool. Don’t want that to get into the body. You’d probably have to seal up any ventilation openings in such a way that crap couldn’t escape.

I’m sure mechanically you’d want it to be as tight of tolerance as you could get away with—you probably don’t want a lot of slop when cutting open some dudes skull. Vibration and such probably play into that tolerance bit…

Of course it could just literally be a rebranded Ryobi or something for all I know. But I’m pretty sure it isn’t. Too many additional requirements means it is probably something slightly fancier.

The ones used in the operating room are different, but for putting traction pins in broken legs (in mid-shaft femur fractures, they will put a pin through the lower part of the femur and hang weights off the end of the bed to straighten the fracture out until the patient can go to surgery), they just use a regular cordless drill since the procedure is not fully sterile.

Wife had a broken leg and they inserted a metal rod in to the bone. She said the operating room sounded like a car repair shop.

100%, orthopedics are intense. They use pneumatic drills and saws so the auto shop analogy isn't far off. In the med device industry ortho docs are often described as mechanics and they often have a lot of physical issues themselves ad they age because it's such hard physical work.

Not long ago I designed a set of bone taps and drills along with a bunch of related instruments and they were designed and made not much differently than high end tools for metal or woodworking.

Strange, I imagine, because you'd have the vibrations and sounds as you describe of the actual cutting, but also the feeling (whatever that's like) of reducing intracranial pressure.

> but I can’t imagine what all the vibrations and sounds passing through skull feels like, especially when power tools are used to drill into the skull or cut out a small section.

I imagine it might be similar to having a cavity filled.

I think it'd be one of the least painful places. The scalp is thin, and isn't overly sensitive, think of how professional wrestlers often cut their scalp on purpose. And I don't think the skull has a ton of nerves in the first place.

A relative had brain surgery for a tumor, and if I'm remembering what she said from fifteen years ago correctly she said the anesthesia shot hurt, than the rest was more a relief than anything as the tumor had been applying constant pressure for years.

> think of how professional wrestlers often cut their scalp on purpose

Wait, what?

(I am even hesitant to ask as I'm not sure I'm ready to hear the answer, whatever it might be.)

So when pro wrestlers bleed there are two ways, blading and hard way. Hard way is exactly as it sounds, someone got hit so hard they got busted open. The second and what the OP is referring to is blading, you get a thin razor blade and nick your scalp-forehead area and you start bleeding. It isn't as extreme as they made it sound.

I just googled it because I've never heard of it before... it's pretty crazy.

Apparently, the wrestlers cut themselves on their scalp / forehead some time into a match to make the match look more intense, with the blood from their head mixing with sweat and dripping down...

A 17 year old kid was even hospitalized due to blood loss from it.

https://en.m.wikipedia.org/wiki/Blading_(professional_wrestl...

Oh wow you're in for a fun day of googling, on the innner world of wrestling. Look up Face, Heel, Turn, Kayfabe, and then go deeper if you want.

Scalps bleed like crazy and they don't hurt much. Plus performing live has some kind of anesthetic quality.

Had that happen to me accidentally. I felt just fine(tm) but everyone was looking at me like i was dying. In hindsight i probably looked like Carrie from Stephen King's novel, could feel the blood on my face.

Bleeding stopped in a minute or two just by holding a towel on the scratched part.

Love that story. I would absolutely flip out if it happened to my wife or kids even knowing what I do.

When you see a wrestler blading or doing a bump, it is still painful. Probably not as painful as it looks, but still painful.

I wasn't trying to imply cutting the scalp would be pain free, but it wouldn't be "excruciatingly painful" like the poster said.

Gotcha.

What weirds me out is that I experienced regular pain in various part of my brain. Not migraines, more like post traumatic sensations with very acute painful areas (front, back, side, center..). Is this only blood vessel nociceptors ?

Those are the nerves running through your skull. That's where a headache comes from. I learned this from having years of migraines.

I'm understanding this right now, from currently having a headache.

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